The value of providing a hydro-fertilizer solution directly to the roots of a tree or other living plant is well known. Horticulturists recommend this method of feeding since the nutrients are directed to a position immediately adjacent to where they are needed. The nutrients are not lost on the surface around the plant, and particularly in compacted and/or clay soils this is the only efficient method available to assure vigorous growth.
Over the years, there have been several proposals for making a root feeder that carries out the function in the most efficient manner. One of the most successful designs in the past is represented by the ROSS root feeder, as illustrated in U.S. Pat. No. 3,618,539. Over the years, there have been several improvements to this basic tool, including improvements to the nozzle portion at the end of the feeder tube, as represented by U.S. Pat. No. 4,705,218. Both of these prior patents are owned by the present assignee
Other designs have appeared including a dual handle model as represented by the Shirley U.S. Pat. No. 4,432,291. The apparent improvement provided by the '291 patent involves an arrangement for dividing the flow into two paths, one for a hydro-fertilizer solution and another for pure water. A simple cut-off and dividing valve is provided for flow control.
Another proposal for modification of the nozzle at the tip of the feeder tube is illustrated in the Platz U.S. Pat. No. 3,783,804. This arrangement involves positioning of annular O-rings and/or annular diaphragm members around the outlet orifices of the nozzle tip, along with a check valve at this point in the flow path to prevent debris from entering the system.
While some of the predecessor root feeders have included a provision for preventing back flow, such as where there is a sudden break in a water line of the municipal system in the vicinity of the site of use, I have discovered an inherent problem in complying with the governmental regulations regarding back-flow prevention. By incorporating the back-flow prevention valve within the hose attachment coupling, under certain conditions during back-flow of the hydro-fertilizer solution, proper release of the solution directly to outside of feeder and onto the ground may not occur. In turn, due to the suction force or siphoning action causing the back flow, the full sealing force of the diaphragm in the back-flow preventer valve may not be realized. In particular, the central bulb of the diaphragm defining the flow path may collapse and be distorted resulting in the possibility of defeating the sealing function of the diaphragm. This can result in some of the hydro-fertilizer solution to leak and be drawn back past the hose attachment coupling and into the municipal water supply. An arrangement that prevents this from happening and that complies fully with the regulations of the Environmental Protection Agency, as well as the strict California regulations, is thus needed.
In the past, very little innovative thinking has gone into improving the structure of the valving arrangement for providing basic flow control including back-flow prevention. Typically, a separate cut-off valve positioned next to the fertilizer mixing bowl and a back-flow preventer valve incorporated into the hose attachment coupling are used. As far as I am aware, there has not been any attempt to integrate the valving arrangement by the designers, or to give consideration to proper positioning of the valves in the flow path, thus typically leading to a generally less efficient feeder, as well as one that is more expensive and difficult to assemble. Thus, there is a need in the art for improvement in the valving arrangement that defines the flow path of the water between the hose attachment coupling and the mixing bowl of the feeder.